Filters, particularly low pass filters, are used extensively in electrical circuits to suppress noise. For high impedance, high frequency circuits pi-network filters are generally used. The pi-network is comprised of a pair of shunt capacitors and an inductive member in series therebetween.
The elimination of high frequency noise is necessary for the transmission of signals through the input/output devices of microcomputers, for example. Both individual pi-network filters and composite pi-network filter assemblies have been used in connectors. Generally, the assemblies such as those disclosed in U.S. Pat. Nos. 4,262,268 and 4,494,092 have capacitor assemblies comprising a pair of dielectric plates having a plurality of openings formed therein for receiving individual terminals. The dielectric plates have a plurality of isolated electrodes formed on one of the opposite faces of the plates adjacent respective openings formed therein for receiving individual terminals and a common electrode formed on the other face of the dielectric plates to provide for ground return. The terminal members extend through one dielectric plate, a tubular or planar magnetic member interposed between the first dielectric plate and a second dielectric plate. The terminals are mechanically and electrically connected to the respective electrodes on each dielectric plate. The assembly also includes means for electrically connecting the common electrodes to an external circuit.
It is an object of the present invention to provide a one piece composite pi-network filter assembly as opposed to the at least three pieces for the assembly described above.
It is a further object of the invention to provide a pi-network filter assembly which can be manufactured with a minimum of fabrication steps.
In addition, it is an object of the invention to provide a high performance pi-network filter assembly.